Resin film for producing decorative laminate and decorative laminate containing the resin film

ABSTRACT

A resin film for use in laminating for producing decorative laminates which is equal or superior to conventional polyvinyl chloride resins in suitability for embossing, processability, and long-term water resistance and can be significantly well-designed; and a decorative laminate in which the resin film has been laminated. The resin film is obtained by compounding a polyester resin with 0.5 to 60 wt. % crystallization accelerator having a particle diameter of 0.01 to 5 μm, forming the mixture into an unstretched film, and embossing at least one side of the film. The resin film is laminated to a metallic or wooden plate, a board, etc. to produce a decorative laminate.

REFERENCE TO RELATED APPLICATIONS

The present application is the national stage under 35 U.S.C. §371 ofinternational application PCT/JP99/06733, filed Jan. 12, 1999 whichdesignated the United States, and which application was not published inthe English language.

INDUSTRIAL FIELD

The present invention relates to a resin film for a decorative platemade from a polyester film with crystallization accelerating agent,wherein the film is embossed so as to form a ruggedness pattern at anouter surface of the resin film. The invention also relates to adecorative plate laminated with the resin film.

BACKGROUND OF THE INVENTION

In the prior art, a film made from soft plastic polyvinylchloride resinwhich is excellent in view of a forming, a design and a chemicalresistance, polyolefin resin such as polyethylene and polypropylene,thermoplastic acrylate resin and fluororesins including fluorine, ametal plate covered with biaxial stretching polyester film and so on, alaminated wooden sheet and a MDF are used for an outer plate and aninner part of construction materials, furniture, electric and electronicappliances, sound equipment and business machines.

The polyvinylchloride resin is excellent in characteristics such aseconomy, embossing and molding. On the other hand, a large amount ofplasticizer is added so as to form and mold the resin easily. Therefore,the resin film is too soft and apt to bleed the plasticizer to a surfaceof the resin film by a long term. In addition, when the resin isburning, toxic substance produced by hydrogen chloride gas is banefulinfluence to the environment. It becomes a serious problem.

Instead of the polyvinylchloride resin, polyolefin resin mainlyincluding polyethylene resin and polypropylene resin have beenconsidered. Although a single layered film made from these resins hasexcellent characteristics in view of embossing and chemical resistance,the film is softer than a plastic polyvinylchloride resin. When theresin is laminated on a metal plate and formed, a design is damaged bywhitening the formed portions. Although any rubber constituent might bemixed so as to avoid for whitening the portions, the resin becomes assoft as the plastic polyvinylchloride resin.

The thermoplastic acrylate resin and the fluororesins have some usefulcharacteristics, respectively. However, these resins are as soft as thepolyvinylchloride resin. Recently, biaxial stretching polyester filmmainly including polyethylene terephthalate as a laminate material ispaid attention. However, when the resin is embossed, a deep, clearruggedness pattern can not be formed easily and the design is not sogood. Moreover, if some kinds of color pigments are mixed into the resinso as to emphasize the ornament effect, the other characteristics suchas forming and water-proof aging would be deteriorated.

To solve the above drawbacks, the present invention provides a resinfilm laminated on a decorative plate having useful characteristics inview of the embossing, forming, water-proof aging and design, which aremore excellent or equal to those of the conventional decorative plateincluding polyvinylchloride resin.

DISCLOSURE OF THE INVENTION

The present invention provides a resin film laminated on a decorativeplate comprising a polyester resin film, wherein crystallizationaccelerating agent has 0.01 to 5 μm in grain diameter and is included0.5 to 60 wt % in weight content and at least one surface of thepolyester resin film is embossed. The crystallization accelerating agentis pigment. The pigment is one or more kinds selected from a group ofcarbon-base pigments, titanium-base pigments, azo compound pigments,cyanine-base pigments. The polyester resin film is a polyethyleneterephthalate resin film. The resin film is laminated on a metal sheet,a wooden sheet or a board.

BEST MODE FOR CARRYING OUT THE INVENTION

The inventors of the present application have been researched acrystallization and the characteristics of resin films. Then, theinventors found that a crystallization speed of the resin influenced toforming and embossing of the resin.

By improving a crystallization speed, the crystallization of the resincan be promoted and the crystallization growth can be controlled so thatthe forming can be improved by increasing number of minute crystalswithout ruining the transparency.

In case of using a decorative plate in water, it is found that adeterioration of the resin could be prevented from promoting. In case ofadding minute resin powder having particle sizes in a predeterminedrange, it was found that the crystallization of the resin was promoted.Thus, the inventors recognized that the minute powder was affected ascrystallization accelerating agent.

The present invention is explained hereinafter.

(Used Substrate)

A metal plate such as a steel plate, an aluminum plate, an aluminumalloy plate, a copper plate, a cooper alloy plate, a zinc-or zinc-alloyplating steel plate is used as a substrate of a decorative plateaccording to the present invention.

Further, a single wooden plate, a laminated wooden plate such as woodveneers and a wood plywood and MDF are also used. Moreover, a plate madefrom inorganic materials such as a plasterboard, a silicic acid calciumboard and an asbestos cement straight board is also used.

The metal plate is an ordinary steel cold rolled steel sheet of 0.10 to1.2 mm in thickness preferably. An ordinary steel cold rolled steel of0.10 to 0.50 mm in thickness is more preferable. Among the cold rolledsteel, low carbon or extra low carbon aluminum killed steel sheet ispreferably used. A non-aging steel sheet in which Nb, Ti or the othersare added, a chromium content steel sheet in which chromium of 3 to 18wt % is included and a stainless steel sheet having various compositionsmay be used. A surface treated steel sheet which gives surface treatmentto the surface of the cold rolled steel sheet may be used. Plating and aconversion treatment and painting processing can be considered as thesurface treatment. As plating, zinc-plating, zinc-aluminum alloyplating, zinc-cobalt-molybdenum plating, tin plating, nickel plating,chromium plating, nickel-phosphorous plating, nickel-zinc plating,nickel-cobalt plating, nickel-tin plating and aluminum plating can beconsidered. As a conversion treatment, chromate treatment and phosphatetreatment and the other well-known methods can be considered. As coatingprocess, various paints may be coated or baked responding to thecharacteristics.

(Used Resin Film)

A film comprising crystal resin is necessary as a resin film for adecorative laminated resin film according to the present invention.Especially, polyethylene terephthalate, polybutylene terephthalate, anda copolymer of polyethylene terephthalate and polybutylene terephthalateand other polyester resins may be used. For instance, one ofterephthalic acids is used and the copolymerization body replaced withisophthalic acid and adipic acid, etc may be used. Further, one ofbutanediol is used and the copolymerization body replaced with ethyleneglycol etc. may be used. Moreover, two kinds or more of the abovementioned blend resins are used. In addition, two kinds or more oflaminated filmsmade from the above mentioned resins may be used as acompound resin film. It is desirable that a thickness 20 to 300 μmpreferable, and especially 70 to 200 μm.

(Crystallization Accelerating Agent Included in a Resin Film)

A resin film laminate on a decorative plate in the present invention isa film made from a crystalline resin including crystallizationaccelerating agent. As minute powder for promoting resincrystallization, pigments ordinary used for paints can be used. Forinstance, one or two more kinds of pigments selects from a groupcomprising carbon-base pigments such as carbon blacks, titanium-basepigments such as titanium white and titanium yellow, inorganic pigmentssuch as red iron oxide, lead white, ultra marine blue pigment, cadmiumyellow, azo compound pigments such as parared, cyanine-based pigmentssuch as phthalocyanine blue and anthraquinone may be used.

The crystallization accelerating agent such as the above describedpigments is utilized as minute powder of which diameter is 0.01 to 5 μm.The diameter is more preferably 0.01 to 0.5 μm. The minute powder iscontained in the resin by 0.5 to 60 wt %. It is more preferable 3 to 40wt %. Even if a grain diameter of minute powder is less than 0.01 μm,improvable effects of crystallization is saturated. On the other hand,if a grain diameter of minute powder is larger than 5 μm, the powder islikely to become the starting point of cracking when some impact isloaded on the resin film.

In case of including the above powder by less than 0.5 wt %, asufficient crystallization effect can not be found. On the other hand,in case of including the above powder by more than 60 wt %, a filmproduction becomes remarkably difficult.

A resin which is excellent in view of forming, embossing quality,water-proof quality (deterioration degree of water-proof quality) can beobtained by containing the above powder in a preferable range (wt %).

(Method for Embossing)

As a method for embossing the above polyester resin film, there is amethod in which a hot melt resin is extruded from a T-die on a ruggedcasting roller so as to form a film of which one side is embossed.Another method employs a step for directly passing a film through a pairof chilled rollers. Another method employs a step for heating a resinand passing the film through a pair of chilled rollers. Another methodemploys a step for passing a film through a rotary screen roller andsucked by vacuum so as to emboss. Another method employs a hot needleprocess, that is, a step for passing a film through a perforator or astep for compressing a film with a stamp roller. An embossing processaccording to the present invention may employ anyone of the methodsdescribed above. Further, the embossing process may employ a step oflaminating the polyester resin film on a substrate, heating thesubstrate in a range of a resin melting point ±10° C., and embossing theresin by compressing with a stamp roller.

An embossing form may be a random mat, a square, a diamond type, a deepdrawing type and a grain. These patterns can be selected depending on aproduct.

(Laminating Method)

The embossed polyester resin film in accordance with the above method islaminated on a substrate by a well known thermal fusing method. In caseof a metal substrate, the metal plate is heated to a temperature higherthan a melting point of a polyester resin, contacted with a non-embossedsurface of the polyester resin. Both are sandwiched by a pair oflaminate roller, and rapidly cooled in water. In case of high adhesivestrength required with respect to a metal substrate, an adhesive layeris provided on the polyester resin or the metal substrate so as tolaminate the metal plate and the polyester resin film through theadhesive layer.

In case of a wood plate or a board, an adhesive layer is provided on apolyester resin film or a substrate so as to laminate the substrate andthe polyester resin film through the adhesive layer.

General adhesive agent may be utilized for an adhesive layer for bodinga polyester resin film and a substrate. For instance, an emulsion typeadhesive agent such as vinyl acetate resin system, ethylene vinylacetate resin system, urea resin system and urethane resin system, etcmay be used. These are safe compounds with the fire, non-stench, cheapin the price.

(Judgement of Embossing Quality)

Embossing quality of the polyester resin film according to the presentinvention is judged by a surface roughness (Ra: μm) of a resin filmafter embossing. In the present invention, the surface of the resin filmis observed by naked eyes and the embossing quality is evaluated by thestandard of the undermentioned three stages:

Excellence: ∘

Little Defective: Δ

Defect: X

The above evaluation standard is judged by measuring the surfaceroughness of the polyvinylchloride resin film with a surface roughnessmeasurement machine (SURFCOM) manufactured by TOKYO SEIMITSU K.K. inaccordance with JIS B0601. In the measurement method, the surfaceroughness of 4 μm is judged as an acceptance standard of the embossingquality. The standard of “excellence” is judged as a case that thesurface roughness of the measured resin film is more excellent or equalto the surface roughness of a polyvinylchloride resin film of 4 μm. Thestandard of “little defective” is judged as a case that the surfaceroughness of the measured resin film is not more excellent than that ofpolyvinylchloride resin film of 4 μm but is no problem in a practicaluse. The standard of “defect” is judged as a case that the surfaceroughness of the measured resin film has problems in a practical use.

(Evaluation of Forming)

A polyester film having a predetermined length and width and a thicknessof 0.10 mm is embossed by passing through a rugged grain stamping rollerof which the surface average roughness Ra is 11 μm at a constant speed.Then, the polyester resin film is heated to a temperature higher thanthe melting point. A zinc-plating steel plate having the same length andwidth with the polyester resin film and a thickness of 0.50 mm iscontacted with the heated polyester resin film and the polyester resinfilm and the sheet are compressed by a pair of rollers so as to put on aspecimen.

The specimen impact loaded by the above described process is examinedwith Dupon shock testing machine (0.5 inch in an outer diameter of theimpact part, 1 kg in weight, and 50 cm in the fall height of the impactpart) in accordance with JIS K5400. The result is evaluated by threestages by naked eye observation as described below.

∘: No crack is generated

Δ: Fine cracks are generated partically in the resin film

X: Cracks are generated at the whole embossed parts of the resin film

In the above points in the evaluation, neither ∘ nor Δ have any problemin use. The examination is executed ten specimens.

(Evaluation of Water-proof Deterioration)

Water-proof deterioration of the polybutylene terephthalate resin filmaccording to the present invention touched water for a long time isevaluated by the Dupon impact test method for imaging the resin filmwith the embossing finish leaving for a long time in the high humidityand high temperature condition (for example, a resin film as an interiormaterial of a unit bath).

A polyester resin film having a predetermined length and width and athickness of 0.10 mm is embossed by passing through a rugged grainstamping roller of which the surface average roughness Ra is 11 μm at aconstant speed. Then, the polyester resin film is heated to atemperature higher than the melting point. A zinc-plating steel sheethaving the same length and width with the polyester resin film and athickness of 0.50 mm is contacted with the heated polyester resin filmand the polyester resin film, and the sheet are compressed by a pair ofrollers so as to put on a specimen. The specimen is cut out to the sizeof 60 mm×60 mm. A cut-out piece is soaked in ion exchanger watermaintained in a temperature of 38±2° C. for one month and dried at theroom temperature. Impact is loaded on the piece by Dupon impact testmachine under the condition in accordance with JIS K 5400 (0.5 inch inouter diameter of impact portion, 1 kg in weight, 50 cm in fall heightof the impact part). The resin film after impacting is observed throughnaked eyes and evaluated by five stages as follows:

5: No crack is generated.

4: Fine cracks are partically generated in the resin film.

3: Fine cracks are generated at the whole embossed portion of the resinfilm.

2: Large cracks are generated at the whole embossed portion of the resinfilm.

1: The whole resin film is remarkably cracked.

In the above points in the evaluation, the points 5 and 4 have noproblem in use. The examination executed ten specimens.

EXAMPLE

Examples of the present invention will be described in detailhereinafter.

Example 1

Polyethylene terephthalate resin and pigments as shown in Table 1 havinga content as shown in Table 1 are mixed and extruded so as to form anon-oriented film having a thickness of 0.10 mm by an extruder. Whilethe film is formed, hot melted resin is extruded from the T-die on arugged casting roller on which the surface average roughness Ra is 11 μmwith a grain and the embossing is operated on one side surface of theresin film. On the contrary, polybutylene terephthalate resin having aquicker crystallization speed is extruded from an extruder so as to forma non-oriented film having a thickness of 0.10 mm of which one sidesurface is embossed as similar as the polyethylene terephthalate resinwithout pigment as a comparative example. Embossing quality of theembossed resin films is observed by naked eyes. The result of theevaluation is a shown in Table 1.

Example 2

A resin film embossed in the same condition of the example 1 islaminated on a metal sheet by a method as described below. The metalsheet is low carbon cold rolled steel sheet having a thickness of 0.50mm with a zinc-plating layer having a thickness of 0.002 mm.

The zinc-plating steel sheet is heated to 280° C. and a non-embossedsurface of the polyethylene terephthalate resin film is contacted withthe zinc-plating steel sheet. The both are compressed by a pair oflaminate rollers and rapidly cooled by immersing into water. Thus, azinc-plating steel sheet covered with a polyethylene terephthalate resinfilm can be obtained.

On the other hand, a zinc-plating steel sheet having the same figure isheated to 240° C. and a non-embossed surface of the polybutyleneterephthalate resin film is contacted with the zinc-plating steel. Theboth are compressed by a pair of laminate rollers and rapidly cooled byimmersing into water. Thus, a zinc-plating steel sheet covered with apolyethylene terephthalate resin film can be obtained.

Regarding the above described zinc-plating steel sheets covered withpolyethylene terephthalate resin film or polybutylene terephthalateresin film, processability of the resin films are evaluated by the Duponimpact test machine under the condition in accordance the JIS K 5400.The result of the evaluation is shown in Table 1.

Specimens having a size 60 mm×60 mm are cut out from the bothzinc-plating steel sheet covered with the respective resins, immersedinto ion exchange water maintained in the temperature of 38±2° C. forone month and dried at the room temperature so as to evaluatewater-proof deterioration of the resin film. The result of theevaluation is shown in Table 1.

Example 3

The resin film embossed under the same condition of the example 1 islaminated on a wooden board as described below. Polyurethane systemadhesive agent (coating weight: 50 g/m²) is coated on a wooden boardhaving a thickness of 6 mm. The polyethylene terephthalate resin film isheated to 180° C. and compressed under the adhesive pressure (15kgf/cm²) for 20 seconds so as to obtain a laminated wooden board coveredwith the polyethylene terephthalate resin film.

Polyurethane system adhesive agent (coating weight: 50 g/m²) is coatedon a wooden board having the same condition as described above and thepolybutylene terephthalate resin film is heated to 160° C. and adheredunder the pressure (15 kgf/cm²) for 20 seconds so as to obtain alaminated wooden board covered with the polybutylene terephthalate resinfilm.

Example 4

A resin film having the same condition of the example 1 is laminated ona sheet by a method as described below. Polyurethane system adhesiveagent (coating weight: 80 g/m²) is coated on a plaster board of 8 mm inthickness and the polyethylene terephthalate resin film is adhered onthe board by heating to 180° C. under the adhesive pressure of 15kgf/cm² for 25 seconds so as to obtain a plaster board covered with thepolyethylene terephthalate resin film.

Polyurethane system adhesive agent (coating weight: 80 g/m²) is coatedon a plaster board having the same condition and the polybutyleneterephthalate resin film is adhered on the board by heating to 160° C.under the adhesive pressure of 15 kgf/cm² for 25 seconds.

The result of the evaluation is shown in Table 1. The polyethyleneterephthalate resin film with pigment has embossing quality, forming andwater-proof deterioration as same as the level of the polybutyleneterephthalate resin film having quicker crystallization speed.

TABLE 1 Crystallization accelerating agent (pigment) Grain Evaluation ofcharacteristics Example or SPECIMEN Resin Diameter Content EmbossingWater-proof comparative No. film kind color (μm) (wt %) quality Formingdeterioration example 1 PET Carbon black Black 0.01 0.5 Δ ∘ 4 Example 2PET Carbon black Black 0.023 3 ∘ ∘ 4 Example 3 PET Carbon black Black0.030 5 ∘ ∘ 5 Example 4 PET Cyanine blue Blue 0.050 3 ∘ ∘ 4 Example 5PET Titanium White 0.25 20 ∘ ∘ 5 Example white 6 PET Titanium White 0.1630 ∘ ∘ 5 Example white 7 PET Titanium White 0.22 40 ∘ ∘ 5 Example white8 PET Parared Red 0.30 60 ∘ Δ 4 Example 9 PET Titanium Yellow 0.20 10 ∘∘ 5 Example yellow 10 PET Ultra marine Ultra blue 5.0 5 ∘ ∘ 4 Exampleblue 11 PET None — — — Δ ∘ 1 comparative example 12 PBT None — — — ∘ ∘ 5comparative example PET: polyethylene terephthalate PBT: polybutyleneterephthalate

POSSIBILITY OF USE IN THE INVENTION

The polyester resin film including crystallization accelerating agentaccording to the present invention has the embossing quality as equal tothat of the polyvinylchloride resin film.

A decorative plate laminated with the polyester resin film has beautifultone and is excellent in the design. The forming and the water-proofdeterioration of the resin film is superior so that the resin film isapplicable to construction material required water resistance such as aunit bath.

What is claimed is:
 1. A resin film laminated on a decorative platecomprising a non-oriented polyester resin film containing acrystallization accelerating agent having a grain diameter of 0.01 to 5μm and included in an amount of 0.5 to 60 wt %, wherein at least onesurface of the polyester resin film is embossed, and wherein said platecomprises a metal sheet, a wooden sheet, or a board made from inorganicmaterials.
 2. A resin film laminated on a decorative plate as claimed inclaim 1, wherein said crystallization accelerating agent is a pigment.3. A resin film laminated on a decorative plate as claimed in claim 2,wherein said pigment is one or more kinds selected from the groupconsisting of carbon-containing pigments, titanium-containing pigments,azo compound pigments, and cyanine-containing pigments.
 4. A resin filmlaminated on a decorative plate as claimed in claim 1, wherein the resinfilm is laminated on a metal sheet.
 5. A resin film laminated on adecorative plate as claimed in claim 1, wherein the resin film islaminated on a wooden sheet.
 6. A resin film laminated on a decorativeplate as claimed in claim 1, wherein the resin film is laminated on aboard.
 7. A resin film laminated on a decorative plate as claimed inclaim 2, wherein the resin film is laminated on a metal sheet.
 8. Aresin film laminated on a decorative plate as claimed in claim 2,wherein the resin film is laminated on a wooden sheet.
 9. A resin filmlaminated on a decorative plate as claimed in claim 2, wherein the resinfilm is laminated on a board.
 10. A resin film laminated on a decorativeplate as claimed in one of claims 1 to 3, wherein said polyester resinfilm is a polyethylene terephthalate resin film.
 11. A resin filmlaminated on a decorative plate as claimed in claim 10, wherein theresin film is laminated on a metal sheet.
 12. A resin film laminated ona decorative plate as claimed in claim 10, wherein the resin film islaminated on a wooden sheet.
 13. A resin film laminated on a decorativeplate as claimed in claim 10, wherein the resin film is laminated on aboard.
 14. The resin film according to claim 1 wherein the polyesterresin film is a film of polybutylene terephthalate or a film of acopolymer of polyethylene terephthalate and polybutylene terephthalate.15. A resin film laminated on a decorative plate comprising anon-oriented polyester resin film containing an additive consistingessentially of a crystallization accelerating agent having a graindiameter of 0.01 to 5 μm and included in an amount of 0.5 to 60 wt %,wherein at least one surface of the polyester resin film is embossed,and wherein said plate comprises a metal sheet, a wooden sheet, or aboard made from inorganic materials thickness.
 16. The resin film ofclaim 15 laminated to a steel sheet, wherein said steel sheet isselected from the group consisting of cold rolled steel sheet of 0.10 to0.50 mm in thickness, non-aging steel sheet containing at least one ofNb and Ti, steel sheet containing 3-18 wt % chromium, and surfacetreated steel sheet, wherein said polyester film has a thickness of70-200 μm, and wherein said crystallization accelerating agent has aparticle diameter of 0.01-0.5 μm and is present in an amount of 3-40 wt%.
 17. The resin film laminated on a decorative plate according to claim14 wherein the polyester resin film is a film of a copolymer ofpolyethylene terephthalate and polybutylene terephthalate, and thecrystallization accelerating agent is selected from the group consistingof one or more of carbon black, titanium dioxide, iron oxide, leadwhite, ultra marine blue, cadmium yellow, an azo compound,phthalocyanine blue, and anthraquinone.